JP2004308338A - Method for pulling out existing pile and pulling-out device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate pile pulling-out work by attaching a pipe for high pressure water injection provided additionally on one side of a seat pile with a short casing and a wire for isolation like a lariat in a lower end part of the casing attached to a lower part of the seat pile with the short casing by a holding member and performing isolation work of the ground around a peripheral wall of the pile and the ground in a pile lower part by injection of high pressure water and pulling up the wire for cutting fringe. <P>SOLUTION: A wire for hoisting the pile and the wire for isolation like a lariat are provided by a plurality of holding members in an upper end part and a lower end part of the seat pile with the short casing to which the short casing made of a steel pipe and having larger diameter than diameter of an existing pile to be pulled out by about 10 cm, respectively, in a tip part of the seat pile. The pipe for high pressure water is additionally provided on one side of the seat pile. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of pulling out existing piles driven into the ground in order to construct a new foundation structure in the ground of this site when rebuilding a new building on the site of a building demolished due to aging etc. And its device.
[0002]
[Prior art]
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-256557 Conventionally, when a building such as a building is rebuilt due to aging of the building or computerization of society, an existing pile remaining in the ground together with the dismantling of the existing building is extracted. It is necessary to newly build a foundation structure such as a foundation pile and a continuous underground wall suitable for supporting the structure of a newly constructed building. Extracting the existing piles remaining in the ground in this way is due to the impact of the existing piles that supported the building to be demolished, especially if the existing piles are concrete piles. Buckling and cracking, buckling and cracking due to partial shear pressure applied to piles during long-term use are not suitable for supporting the structure of newly built buildings, Even if buckling or cracking does not occur, the existence of existing piles is an obstacle to construction when constructing a new foundation structure due to the structure and shape of the newly constructed building.
[0003]
Conventionally, as a method of pulling out existing concrete piles remaining in the ground from the ground, using a swiveling excavator, excavating the ground around the pile wall over the entire length of the pile and cutting off the pile and ground. After the pile was pulled out of the pile, the pile was cracked or broken due to the pile installation or long-term use.The lower part of the pile was left behind in the ground. May be. For this reason, a guide steel pipe is driven into the pile hole after the upper part of the pile has been pulled out, and then a steel sheet pile having a short casing pipe attached to the lower part is driven by using the guide steel pipe as a guide. The wire rope attached to the upper edge of the pile is pulled up and wrapped tightly around the pile left behind in the ground, and the pile is taken out by pulling up the wire rope with a crane. 1) is known.
[0004]
The drawing method described in Patent Document 1 will be described with reference to FIGS. FIG. 13 is a perspective view of a tip casing used for pulling out a conventionally known remaining pile, and FIG. 14 is a diagram showing a state where the tip casing is driven into the casing pipe until the upper portion of the remaining pile projects from the casing pipe. FIG. 4 is a diagram showing a state in which a tip end of a base wire rope wound around a casing tube is moved and wound around an upper part of a remaining pile.
[0005]
The ground around the peripheral wall of the existing pile is excavated in the length direction of the existing pile using a rotary excavator, and the peripheral wall of the existing pile is cut off from the ground. After that, the wire rope hung on the upper part of the existing pile is pulled up by a crane truck and the pile is pulled out, or the pile is pulled out by a hydraulic pile remover. However, as mentioned above, existing piles made of concrete piles are subject to buckling and cracking due to the impact during casting and the partial shear pressure applied to the piles during long-term use due to ground pressure. When the existing pile is pulled out, the pile is cut at the buckling or crack location, and the lower part of the existing pile is left in the ground.
[0006]
Then, in order to pull out the lower part of the existing pile left in the ground, a vibrator in which a guide steel pipe 39 is attached by a first hoisting wire rope 35 by a crane truck 34 to a pile hole from which the existing pile in the upper part has been pulled out. The guide steel pipe 39 is hung from the pile hole by suspending the hammer 37, and the tip of the guide steel pipe 39 is fitted to the upper part of the remaining pile 38 left in the ground. On the other hand, the tip casing used in the method of pulling out the lower part of the existing pile left in the ground is constituted by fixing a short steel pipe casing pipe 31 to the tip of a steel sheet pile 30. At the upper end of the casing tube 31, the holding members 32 of the mounting wire rope 33 are attached at regular intervals. The holding member 32 is a small-diameter steel wire bent into a semicircle, and both ends thereof are attached to the casing tube 31 by welding. The distal end of the mounting wire rope 33 is wound around the outer periphery of the casing tube 31 through the semicircular hole of the holding member 32.
[0007]
Then, the tip casing is driven by the vibratory hammer 37 with the guide steel pipe 39 as a guide until the upper portion of the remaining pile 38 protrudes from the casing pipe 31 by a certain length, thereby cutting off the friction between the remaining pile 38 and the ground. Thereafter, when the base wire rope 33 is wound up, the base wire rope 33 wound around the upper end of the casing tube 31 by the holding member 32 peels the holding member 32 from the casing tube 31, and the tip of the base wire rope 33. While the part is being lifted and squeezed, it is tightly wound around the upper part of the remaining pile 38, and furthermore, the remaining pile 38 is taken out to the ground by pulling up the mounting wire rope 33 with the first hoisting wire rope 35 from the crane truck 34.
[0008]
[Problems to be solved by the invention]
However, in the above-mentioned conventional method of drawing out the remaining pile, as a construction device for pulling out the existing pile in the ground, first, the ground around the peripheral wall of the existing pile, which is a construction device for cutting the existing pile and the ground, is used. A swivel-type excavator for excavation, and then a tip casing in which a short steel pipe casing pipe is fixed to the tip of a steel sheet pile for pulling out the lower part of the existing pile left in the ground, and this tip casing It requires a vibro hammer, which is a driving device. As described above, a plurality of construction apparatuses must be prepared for different operations, and a large number of construction apparatuses make a narrow construction site narrower and more complicated, and a large amount of expense is required to prepare the plurality of construction apparatuses. are doing.
[0009]
In addition, the tip of the lower part (remaining pile) of the pile left in the ground and the ground are tightly integrated by compaction due to the load from the upper structure during casting and long-term use, Extracting it with a wire rope is a very difficult task.
[0010]
Therefore, the present invention has been made in view of the above-mentioned problem, and in order to pull out the entire length of an existing concrete pile from the ground, the entire length of the pile between the ground and the existing pile by injection of high-pressure jet water and driving of a short casing is described. To cut off the lower part of the existing pile that was cut at the point of buckling or cracking due to the impact of casting and long-term use, cutting the lower part of the lower part of the existing pile and the ground It is an object of the present invention to provide a method of pulling out an existing pile, in which the work is performed by one construction device, and a pulling device used for the method.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 of the present invention is to fix a short casing slightly larger in diameter than an existing pile to a lower portion of a sheet pile and to fit the casing to the existing pile while attaching the casing to the existing pile. The sheet pile is driven in by driving means while high-pressure water is injected from the injection nozzle at the lower end of the high-pressure water pipe attached in the length direction of the sheet pile, and a step of trimming the peripheral wall of the existing pile and the ground is performed. After the upper end of the existing pile is driven below the lower end of the existing pile, pull the wire rope for trimming to trim the lower end of the existing pile and the ground, then pull the wire rope for lifting and tighten the lower end of the existing pile, Pulling process of existing piles by pulling means and lifting wire rope,
Characterized by the following steps:
[0012]
In order to achieve the above object, the invention according to claim 2 of the present invention is characterized in that a short casing slightly larger in diameter than an existing pile is fixed to a lower portion of a sheet pile and the casing is fitted to the existing pile. The sheet pile is driven in by driving means while the high-pressure water is injected from the lower end of the high-pressure water pipe attached in the length direction of the sheet pile, and the peripheral wall of the existing pile is cut off from the ground, a short casing. With the sheet pile withdrawing and the existing pile being pulled out, the upper end of the casing is driven into the lower part of the lower pile, and the lower end of the lower part of the pile where the rim wire rope is pulled and the ground is left is pulled. Beveling process, binding process of the lower end of the lower portion of the pile left by pulling the lifting wire rope, pulling out the lower portion of the pile left by the pulling means and the lifting wire rope,
Characterized by the following steps:
[0013]
Further, in order to achieve the above object, the invention according to claim 3 of the present invention provides a pipe for high-pressure water having a short casing slightly larger in diameter than an existing pile and fixed at a lower portion and having a jet nozzle at a lower end. , A sheet pile provided in the length direction thereof, a driving / pulling-out means for the sheet pile, and a plurality of holding members for lifting the entire circumference of the upper edge of the short casing and the entire circumference of the lower edge of the casing. A high-pressure water supply means is connected to an upper end of the high-pressure water pipe, with a wire rope and a trimming wire rope attached.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a method for pulling out an existing pile and an apparatus for pulling out an existing pile according to the present invention will be described with reference to FIGS. FIG. 1 is an overall view of a sheet pile with a short casing used for pulling out an existing pile of the present invention, FIG. 2 is a plan sectional view of a sheet pile with a short casing used for pulling out an existing pile of the present invention, and FIG. FIG. 4 is a cross-sectional view of a sheet pile with a short casing used for pulling out an existing pile of the present invention, FIG. 4 is a connection state diagram of a sheet pile having a casing at a lower portion of the present invention and high-pressure water supply means, and FIG. FIG. 6 is a state diagram of the existing pile pulling device of the present invention before installation, FIG. 6 is a state diagram of the existing pile pulling device of the present invention in which a pile lifting wire is set, and FIG. 7 is an existing state of the present invention. FIG. 8 is a diagram showing a state where the existing pile is pulled up by the pile pulling device, FIG. 8 is a diagram showing a state where the existing pile is pulled down by the existing pile pulling device of the present invention, and FIG. 9 is a casing below the existing pile pulling device of the present invention. Of sheet pile with FIG. 10 is a diagram showing a lifted state, FIG. 10 is a diagram showing a state of solidification material injection processing into a pile hole after the existing pile is drawn out of the present invention, and FIG. 11 is a state of backfilling the pile hole after the existing pile is drawn out according to the present invention. FIG. 12 is a state diagram of an existing pile pulling-out device according to another embodiment of the present invention before being built.
[0015]
The sheet pile A with the short casing used for the operation of pulling out the existing pile of the present invention shown in FIGS. 1 to 12 has a short diameter about 10 cm larger than the diameter of the existing pile 8 pulled out at the tip of the sheet pile 1. The casing 2 made of steel pipe is fixedly mounted, and holding members 5, 5,... Of the wire 7 for lifting piles are attached to the upper end of the casing 2 at regular intervals. The tips of the pile lifting wires 7 are wound around the outer periphery of the casing 2 around the holding members 5, 5,... Attached at regular intervals to form a loop at one end, and the other pile is attached to this loop. The end of the lifting wire 7 has a lasso shape.
[0016]
The tip of the other pile lifting wire 7 passed through the loop portion is extended to the upper end of the sheet pile A with the short casing, and is hooked on a hook of a hanging wire 16 of a crane truck 15 described later. ing. The holding member 5 is configured such that the pile lifting wire 7 is cut by lifting the hanging wire 16 of the crane truck 15, and the pile lifting wire 7 is separated from the peripheral wall of the casing 2.
[0017]
The lower end of the casing 2 attached to the tip of the sheet pile A with the short casing is folded inward and bent to form a wire receiving portion 9, and the wire receiving portion 9 is cut off at regular intervals so as to surround the wire receiving portion 9. The holding members 5, 5,... Of the application wire 6 are attached. The distal ends of the trimming wires 6 are passed through the holding members 5, 5,... Attached to the wire holder 9 of the casing 2 to form a loop at one end. Is formed into a lasso through the tip of the edge cutting wire 6.
[0018]
The tip of the other edge cutting wire 6 passed through the loop portion is extended toward the upper end of the sheet pile A with the short casing, and is hooked on a hook of a hanging wire 16 of a crane truck 15 described later. I have. The holding member 5 holding the edging wire 6 is also cut by the lifting of the hanging wire 16 of the crane truck 15 so that the pile lifting wire 7 is detached from the inner peripheral wall of the casing 2. It has become. The wire receiving portion 9 is a protection portion for preventing the edging wire 6 from coming off the casing 2 when the sheet pile A with the short casing is driven.
[0019]
On one side of the sheet pile A with the short casing, a pipe 3 having a connection port at an upper end and an injection nozzle 14 at a lower end is attached along the entire length, and the attached pipe 3 is a cover body 4. Protected by The sheet pile A with the short casing can be connected to a connection sheet pile 10 provided with a pipe 3 protected by a cover body 4 over the entire length so as to correspond to the length of the existing pile 8 in the ground. It has become.
[0020]
The high-pressure water is supplied from the water tank 13 installed near the work place and the high-pressure water supply means 11 through the water supply hose 12 through the pipe 3 attached to the sheet pile A with the short casing and the sheet pile A with the short casing. High-pressure water is injected from the injection nozzle 14 at the lower end of the casing 2 attached to the tip of the casing 2, and the ground between the inner peripheral wall of the casing 2 and the existing pile 8 is muddy. 8 can be easily pulled out.
[0021]
Next, an existing pile pulling method using the sheet pile with the short casing of the present invention and an operation procedure of the existing pile pulling apparatus will be described with reference to FIGS.
[First step]
First, a vibratory pile driver 17 is suspended from a crane truck 15 installed near an existing pile 8 to be pulled out to a suspension wire 16, and a sheet pile A with a short casing is gripped by the vibratory pile driver 17. The casing 2 provided at the lower end of the sheet pile A with the short casing is fitted on the exposed head of the existing pile 8.
[0022]
[Second step]
Next, the water in the water tank 13 is jet-sprayed from the jet nozzle 14 at the lower end of the pipe 3 attached to one side of the sheet pile A with the short casing via the water supply hose 12 by the high-pressure water supply means 11. The vibratory pile driver 17 is operated to drive the sheet pile A with the short casing into the ground. Then, the casing 2 provided at the lower end of the sheet pile A with the short casing is driven into the ground, and the ground between the inside of the casing 2 and around the existing pile 8 is broken by the jet injection a from the injection nozzle 14. The soil is muddy and the peripheral wall of the existing pile 8 is cut off from the ground.
[0023]
[Third step]
Then, the edge cutting wire 6 attached by the plurality of holding members 5 to the wire receiving portion 9 below the short casing 2 attached to the lower portion of the sheet pile A with the short casing is suspended from the crane truck 15. When the lifting member is lifted by a lowering wire (not shown), the holding member 5 is cut by pulling the edging wire 6, the edging wire 6 is separated from the short casing 2, and furthermore, a crane vehicle 15 (not shown) is used. When pulled up by the hanging wire, the lasso-shaped edge cutting wire 6 is further narrowed, so that the ground between the lower part of the existing pile 8 and the lower part of the existing pile 8 is cut by the wire. For this reason, the lower part of the existing pile 8 and the ground can be cut off.
[0024]
[Fourth step]
Similarly, a suspension wire 7 suspended from a crane truck 15 is a pile lifting wire 7 attached to a short casing 2 attached to a lower portion of a sheet pile A with a short casing by a plurality of holding members 5 (shown in FIG. (Not shown), the holding member 5 is cut by pulling the pile lifting wire 7, the pile lifting wire 7 is detached from the short casing 2, and the pile lifting wire 7 becomes lasso-shaped. Therefore, the lower end of the existing pile 8 is tightened.
[0025]
[Fifth step]
Then, the sheet pile A with the short casing is lifted and pulled out by the suspension wire 16 suspended from the crane truck 15, and the existing pile is suspended by the vibration type pile driver 17 suspended similarly to the suspension wire 16 from the crane truck 15. When the 8 is pulled out, the peripheral wall and lower end of the existing pile 8, the ground, and the edge have already been cut, so that the pile 8 can be easily pulled out.
[0026]
[Sixth step]
In this way, the muddy water is injected by the muddy water injection device 27 into the hollow of the pile hole 22 from which the existing pile 8 has been pulled out by the muddy water injection hose 26, and the hole wall of the hollow pile hole 22 is self-standing. The muddy water is pumped up by a sand pump 19 and sent to a treatment plant for muddy water treatment. Thereafter, a solidifying material such as cement is kneaded by the solidifying material supply device 20 and injected into the pile hole 22 by the injection pipe 21, and soil and the like are buried back into the pile hole 22 by the excavating device 23 and the backfill portion. 24 are formed.
[0027]
In the above-described process, when the existing concrete pile 8 is cut at the place of buckling or cracking due to the impact at the time of driving or long-term use, and the lower part of the existing pile is a remaining pile, First, as [Step A], the above-described steps [First Step] and [Second Step] are performed.
[0028]
[Step B]
A suspension wire suspended from a suspension wire 16 suspended from a crane truck 15 is hung above the existing pile 8 and a sheet pile A with a short casing and the existing pile 8 are suspended by the suspension wire 16 of the crane vehicle 15. Pull out.
[0029]
[Step C]
Then, the upper end of the casing 2 of the sheet pile A with the short casing is again driven into the pile hole from which only the upper part of the existing pile 8 has been pulled out, below the remaining pile in the lower part. Thereafter, the edge cutting wire 6 attached to the wire receiving portion 9 at the lower portion of the casing 2 by the plurality of holding members 5 is lifted by a hanging wire (not shown) suspended from the crane truck 15 to perform edge cutting. When the holding member 5 is cut by pulling the wire 6 for use, the edge cutting wire 6 is detached from the short casing 2 and further pulled up by a hanging wire from a crane truck 15 (not shown) to form a lasso. Since the cutting wire 6 is further narrowed, the ground below the remaining pile in the lower part is cut by the wire, and the lower part of the remaining pile in the lower part and the ground are cut.
[0030]
[Step D]
Similarly, a suspension wire 7 suspended from a crane truck 15 is a pile lifting wire 7 attached to a short casing 2 attached to a lower portion of a sheet pile A with a short casing by a plurality of holding members 5 (shown in FIG. (Not shown), the holding member 5 is cut by pulling the pile lifting wire 7, the pile lifting wire 7 is detached from the short casing 2, and the pile lifting wire 7 becomes lasso-shaped. The lower end of the remaining pile in the lower part.
[0031]
[Step E]
Then, the sheet pile A with the short casing is lifted and pulled out by the hanging wire 16 hung from the crane truck 15, and the lower portion is driven by the vibratory pile driver 17 hung from the crane truck 15 as well as the hanging wire 16. When the remaining pile is pulled out, the peripheral wall and lower end of the remaining pile at the lower portion, the ground, and the edge are already cut, so that the pile can be easily pulled out. Thereafter, the above [sixth step] is performed.
[0032]
In addition, in an area or a time zone in which vibration is restricted during work due to environmental considerations, instead of the vibratory pile driver 17, a hydraulic pile driver is used instead of the vibratory pile driver 17 as a driving means for the sheet pile A with the short casing. The sheet pile A with the short casing may be driven or pulled by the machine 25.
[0033]
As described above, in the existing pile pulling method and the pulling device of the present invention, unlike the conventional construction method, without loading a plurality of different types of construction devices into the construction site, a single construction device can be used for concrete. The lower part of the existing pile or the existing pile cut off in the middle and remaining in the ground can be pulled out.
[0034]
Also, in order to pull out the existing pile made of concrete or the lower part of the existing pile that has been cut off in the middle, a short casing is attached to the lower part of the sheet pile, and lassos are respectively attached to the upper end and the lower end of the casing. Pile lifting wire and edge cutting wire are attached by a plurality of holding members, and this short casing is attached to the lower part of the sheet pile. And the high-pressure water injection device attached to one side of the sheet pile, the existing pile to be pulled out is fitted and set in the short casing, and the peripheral wall of the existing pile and the ground are cut off. it can.
[0035]
Since the bottom of the existing pile and the ground are cut off by the lasso-shaped cutting wire attached to the lower end of the short casing with a plurality of holding members, the peripheral wall and the bottom of the existing pile and the ground are cut off. Since the rim is sufficiently cut, the work of pulling out the existing pile can be easily performed. Also, even if the existing concrete pile is cracked or cut in the middle during casting or long-term use, even if the lower part of the pile remains in the ground at the time of pulling out, other construction equipment is narrow. Without being carried into the construction site, the lower part of the existing pile that is cut in the middle by the single construction device and remains in the ground can be pulled out.
[0036]
【The invention's effect】
As described above, the inventions according to the first, second, and third aspects of the present invention have the following effects.
1) A high-pressure water injection device attached to one side of a sheet pile with a short casing, and a lasso-shaped trimming wire are attached to a lower end of a casing attached to a lower portion of the sheet pile with a short casing by a holding member. Since the cutting work with the ground around the peripheral wall of the pile and the ground under the pile is performed, the work of pulling out the pile can be easily performed.
2) It is possible to pull out the existing concrete pile or the lower part of the existing pile that has been cut and left in the middle with one construction equipment without carrying in a plurality of different construction equipment, and the cost required for the construction equipment Can be reduced. For this reason, even if it is a narrow construction site, it will not be complicated by a plurality of construction apparatuses.
[Brief description of the drawings]
FIG. 1 is an overall view of a sheet pile with a short casing used for pulling out an existing pile according to the present invention;
FIG. 2 is a plan sectional view of a sheet pile with a short casing used for pulling out an existing pile according to the present invention;
FIG. 3 is a cross-sectional view of a sheet pile with a short casing used for pulling out an existing pile according to the present invention;
FIG. 4 is a connection state diagram of a sheet pile having a casing at a lower portion of the present invention and high-pressure water supply means,
FIG. 5 is a state diagram of the existing pile pulling out device of the present invention before being built,
FIG. 6 is a state diagram before setting a pile lifting wire set in the existing pile pulling device of the present invention,
FIG. 7 is a view showing a state in which an existing pile is pulled by the existing pile pulling device of the present invention;
FIG. 8 is a diagram showing a state in which an existing pile is pulled down by the existing pile pulling device of the present invention;
FIG. 9 is a view showing a state in which a sheet pile having a casing is provided at a lower portion of an existing pile pulling device of the present invention,
FIG. 10 is a view showing a state of solidification material injection processing into a pile hole after pulling out an existing pile according to the present invention;
FIG. 11 is a diagram showing a state of backfilling a pile hole after pulling out an existing pile according to the present invention;
FIG. 12 is a state diagram of an existing pile pulling-out device according to another embodiment of the present invention before installation.
FIG. 13 is a perspective view of a tip casing used for pulling out a conventionally known remaining pile,
FIG. 14 is a diagram showing a state in which the tip casing is driven into the casing tube until the upper portion of the remaining pile projects from the casing pipe;
FIG. 15 is a view showing a state in which a tip end of a base wire rope wound around a casing tube is moved and wound around an upper part of a remaining pile.
[Explanation of symbols]
A sheet pile with short casing, 1 sheet pile,
2 casing, 3 piping, 4 cover body, 5 holding member,
6 Edge cutting wire, 7 Pile lifting wire, 8 Existing pile,
9 wire receiving section, 10 connection sheet pile, 11 high-pressure water supply means,
12 water supply hose, 13 water tank, 14 injection nozzle, 15 crane truck,
16 hanging wire, 17 vibratory pile driver, 18 lifting wire,
19 sand pump, 20 solidified material supply device, 21 injection pipe,
22 pile holes, 23 drilling rig, 24 backfilling section, 25 hydraulic pile driver,
26 Mud injection hose, 27 Mud injection device.

Claims (3)

A short casing with a diameter slightly larger than that of the existing pile is fixed to the lower part of the sheet pile, and the casing is fitted to the existing pile, and the lower end of the pipe for high-pressure water attached in the length direction of the sheet pile is injected. The sheet pile is driven by the driving means while high-pressure water is sprayed from the nozzle, and the peripheral wall of the existing pile is cut off from the ground,
After driving the upper end of the casing below the lower end of the existing pile, pulling a wire rope for trimming, the step of trimming the lower end of the existing pile and the ground,
Next, pull the wire rope for lifting and tighten the lower end of the existing pile,
Drawing process of sheet pile with short casing,
Pulling process of existing piles by pulling means and lifting wire rope,
A method for pulling out existing piles, comprising the following steps: A short casing with a diameter slightly larger than that of the existing pile is fixed to the lower part of the sheet pile, and the casing is fitted to the existing pile, and the lower end of the pipe for high-pressure water attached in the length direction of the sheet pile is injected. The sheet pile is driven by the driving means while high-pressure water is sprayed from the nozzle, and the peripheral wall of the existing pile is cut off from the ground,
Pulling out sheet pile with short casing and pulling out existing pile,
A beveling step between the lower end of the lower portion of the lower portion of the pile left behind by pulling the wire rope for trimming after being driven below the lower portion of the pile where the upper end of the casing is left, and the ground,
Tightening process of the lower end of the lower part of the pile left by pulling the lifting wire rope,
Pulling process of the lower pile left by the pulling means and the lifting wire rope,
Characterized by the following steps: A sheet pile in which a short casing slightly larger in diameter than the existing pile is fixed at the bottom and a pipe for high-pressure water having an injection nozzle at the lower end is added in the length direction, and a driving / pulling-out means for the sheet pile, A plurality of lifting wire ropes and edge wire ropes are attached to the entire circumference of the upper edge of the short casing and the entire circumference of the lower edge of the casing, respectively. An existing pile pulling-out device to which a water supply means is connected.

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